Method of cleaning scaled and soiled



United States Patent METHOD OF CLEANING SCALED AND SUILED WIRES 0R BANDS Rudolf Kaiser, Dusseldorf, Germany, assignor to Langbein-Pfanhauser Werke A. G., Dusseldorf, Germany No Drawing. Application March 29, 1954, 7 Serial No. 425,753

Claims priority, application Germany March 31, 1953 Claims. (Cl. 51-481) comes true'for the adherence of galvanic zinc coats and other metal coats. Tests have shown that insufficient adherence and a low ductility of zinc coats are essentially due to the formation of hard zinc in the galvanizing tank and that such drawbacks may largely be eliminated by reducing the thickness of hard zinc layer of the coat. The thickness of the hard zinc layer depends upon the immersion time in the molten zinc. This immersion time may be considerably shortened if the wire or band has an absolutely clean surface as this permits the wire or band to receive the zinc coat in the melting bath immediately. V

The problem of surface cleaning is equally existent for the electro-galvanizing of Wires. Also in this case the adherence of relatively thick zinc layers depends upon the same circumstances.

It is an object of my invention to solve the problem of cleaning scaled and soiled Wires, bands or the like in an economical manner such as to provide a perfectly clean surface on a wire or band showing a ductile zinc coat already after a short immersion time and assuring strong adherence of the metal coat also when being electro-galvanized. Hitherto it was usual to subject the wires or bands prior to galvanizing to a chemical or electrolytic preparation with subsequent rinsing and thereafter to remove the residues still existing on the surface despite pickling by stripping them offmechanically. This stripping oflt' procedure generally was effected by passing the wires or bands through an elongated sand bath.

It has been found in practice that passing of a wire through sand being at rest implies the recurrent formation of grooves even with a considerable dumping height which renders the stripping off procedure insufficient. Contrary to that the method according to my invention comprises passing the wire or band after an electrolytic treatment in acid or alkaline electrolytes through moving granular scouring means. In this way the forementioned drawbacks of the prior art methods are eliminated as the movement of the granular scouring means prevents the formation of grooves by the wires or bands and assures a considerably more etficient cleaning of their surfaces.

Conveniently scouring will be effected between two electrolytic treatments. The scale dried in the first electrolytic bath is removed by scouring so that it is no problem to remove the remaining residue completely by a second electrolytic treatment, the sequence of the treatments being unessential, such as anodic or cathodic and acid or alkaline.

For carrying out the method according to my invention it is convenient to have the scouring means in shallow boxes which are rapidly reciprocated and through which the wires or bands are passed. As scouring means various materials such as scrap glass, coke, pumice or similar materials of suitable granulation may be used.

I claim:

1. A method of cleaning scaled and soiled wires or. bands which comprises first, electrolytically treating the wires or bands, and thereafter, pulling them through a granular scouring substance composed of particles free to move relative to one another in any direction While simultaneously subjecting said substance to violent agitation in a manner that will cause an irregular continuously changing distribution of particles about said wire or band.

2. A method as in claim 1, further including maintaining the Wire or hand against lateral deviation in any direction from the path followed thereby while it is being pulled through said substance.

3. A method as in claim 1 wherein the scouring substance is reduced to a coarse granular state from a material selected from the group consisting of scrap glass, coke, and pumice. 1 Y

4. A method as in claim 1 wherein the electrolytic treatment of the Wire or band is carried out in an acid electrolyte.

5. A method as in claim 1, wherein the electrolytic treatment of the wire or band is carried out in an alkaline electrolyte.

References Cited in the file of this patent UNITED STATES PATENTS 380,162 Baumeister Mar. 27, 1888 969,179 Murphy Sept. 6, 1910 1,211,138 Gravell Jan. 2, 1917 1,403,727 Zabel Jan. 17, 1922 1,678,359 Schulte July 24, 1928 2,372,599 Nachtman Mar. 27, 1945 2,531,132 Johnson Nov. 21, 1950 2,540,367 Hamilton Feb. 6, 1951 2,554,701 Hackett May 29, 1951 

